The case of a schoolgirl in China buying a so-called copying robot to write her homework has caused many social media users to leap to her defence and fuelled growing interest in the machines.

Her mother “Zhang” in the northeast city of Harbin had discovered that her daughter, aged about 15, had bought the robot to help her complete homework during the Lunar New Year holiday. She used it for exercises such as copying passages from a textbook and writing essays.

Despite festivities and travelling leaving little time for the assignments, Zhang was amazed when her daughter finished all her text-copying in two days, with neat writing, the report said.

But while cleaning the girl’s room, Zhang found the device – a metal frame and pen, with packaging claiming it could “imitate all sorts of handwriting”.

It turned out that her daughter had spent more than 800 yuan (about US$120) to buy it online using her lai see – the packet of money given during the new year for luck. Angered by a demonstration she watched on how the robot could copy homework, Zhang smashed the appliance.

“It can help you with homework, but can it help you on tests?” Zhang was quoted as saying.